Paul Kersey, who had left New York City for Chicago, now is managing a radio station in Los Angeles. With him is his daughter Carol, slowly recovering from the catatonic effects of a terrible assault on her, when her mother had been killed and her father embarked upon his determined hunt for criminal's in the city's subways, streets and parks. Paul's pocket is picked and his wallet stolen by a group of five street punks. He pursues and catches one of them. Angered by Paul's pursuit, the gang goes to his apartment, beat Paul up, kill his housekeeper, rape and kill Carol. Paul's nightmare has begun and the presence of Barbara, a radio reporter he has become attracted to, does little to alleviate it. Paul prowls the streets, hunting and slowly unearthing the killers. His vengeance crusade leads to LA Police Department fears that New York City's former vigilante is now operating on their territory. And, in New York City, word of what is happening in Los Angeles frightens the DA, the Chief of Police and the Police Inspector who had conspired to let Kersey leave town rather than put him on trial for the killings. Now, if he is captured in LA, and talks, they will be in serious trouble. To prevent this, Police Inspector Ochoa goes to California to stop Paul Kersey once and for all.